“I watched for about four days," he said, explaining that he found the computer being used at the home of a family in the South End’s Cathedral Public Housing Complex. "I was giving information to police, and the whole time he didn’t know this was going on at all, that I could see what he was doing," Harrington added.

It turns out that the teen also didn't know that the computer he was using was stolen.

"I found out it was bought by a family living in the projects, and that they had no idea they were buying a stolen computer," Harrington told the news channel. The family had purchased the computer for their son who was heading off to college.